Adding some comments to confirmation height store

nano/secure/common.hpp

@@ -225,9 +225,14 @@ class confirmation_height_info final
 public:
 	confirmation_height_info () = default;
 	confirmation_height_info (uint64_t, nano::block_hash const &);
+
 	void serialize (nano::stream &) const;
 	bool deserialize (nano::stream &);
+
+	/** height of the cemented frontier */
 	uint64_t height{};
+
+	/** hash of the highest cemented block, the cemented/confirmed frontier */
 	nano::block_hash frontier{};
 };
 

nano/secure/store.hpp

@@ -725,7 +725,14 @@ class confirmation_height_store
 {
 public:
 	virtual void put (nano::write_transaction const & transaction_a, nano::account const & account_a, nano::confirmation_height_info const & confirmation_height_info_a) = 0;
+
+	/** Retrieves confirmation height info relating to an account.
+	 *  The parameter confirmation_height_info_a is always written.
+	 *  On error, the confirmation height and frontier hash are set to 0.
+	 *  Ruturns true on error, false on success.
+	 */
 	virtual bool get (nano::transaction const & transaction_a, nano::account const & account_a, nano::confirmation_height_info & confirmation_height_info_a) = 0;
+
 	virtual bool exists (nano::transaction const & transaction_a, nano::account const & account_a) const = 0;
 	virtual void del (nano::write_transaction const & transaction_a, nano::account const & account_a) = 0;
 	virtual uint64_t count (nano::transaction const & transaction_a) = 0;